An exceptionally stylish and dynamic martial-arts movie, "Cage" (citywide) takes its title from an enclosed and padlocked ring in which two men square off. No weapons are allowed, and it is not unusual for the matches to end in the death of one of the combatants. Huge sums of money are wagered on these illegal contests, which the film's writer Hugh Kelley, a martial-arts champion himself, claims to have observed in Hong Kong and other foreign cities.

However, in "Cage," these so-called human cockfights take place in an old warehouse in the industrial section of Los Angeles. The large and brawny Lou Ferrigno and Reb Brown star as buddies from their days in Vietnam, and the entire film is tautly and plausibly constructed to maneuver these friends into the cage operated by a suave and utterly ruthless underworld kingpin, Tin Lum Yin (James Shigeta).

In a deft opening credit montage, director Lang Elliott shows how the superhumanly strong Billy (Ferrigno) managed to save the life of Scott (Brown) in 'Nam but suffered permanent brain damage from his own wounds. Once the credits are over, we move to the present. Scott is now a struggling bar owner who lovingly cares for the childlike Billy; in their off hours they work out in the modest home they share. It is Billy's innocence that makes them vulnerable to small-time hood and compulsive gambler Tony Baccola (Michael Dante), deeply into debt to Tin Lum Yin.

Not surprisingly, "Cage" is a brutal business, but no more so than a rather different gladiator film, "Spartacus." What is surprising in this swift and energetic picture is what juicy parts it offers its array of seasoned actors. Ferrigno does his best work to date as the sweet-natured, all-too-trusting Billy, and Brown displays sensitivity and passion as the kindly Scott. In addition to the film's key featured players, Dante and Shigeta (who brings a Shakespearean flourish to his villain), there is Mike Moroff (as Dante's much put-upon sidekick), Al Leong (as an undercover cop), Branscombe Richmond (as a rage-filled member of a street gang) and Al Ruscio (in a definitive portrayal of the classic old-time mobster). The various cage fighters are played by champions in the various martial arts.

In essence, "Cage" is a sentimental macho fantasy about male bonding, and as such its women are peripheral. Contributing substantially to the film's impact are Jacques Haitkin's dark-hued camera work and Michael Wetherwax's driving score. "Cage" (rated R for violence) is an example of modestly budgeted exploitation film making at its most dedicated.